Multi-image display devices of various kinds are known. Such devices are used for advertisement, instructional purposes, providing directions, games and many other uses. These devices usually contain prisms revolving about their axes, or alternatively, devices projecting movies in a closed cycle. All such devices, however, require a substantial amount of electrical power for their operation, hence requiring connection to electrical mains. Furthermore, such devices are of necessity of a substantial size, due to the relative complexity of the required drive means and other parts thereof.
The basic optical principle of displacing a complex lithographic print relative to a lenticular lens array has been known from the prior art, e.g., U.S. Pat. No. 5,494,445, which discloses general know-how for alternatively displaying several images. However, to date, this knowledge has not been properly utilized for advertising purposes. There exists a need for a dynamic, multi-image display to be used in shopping centers and other locations, which is capable of functioning independently when affixed to walls or attached to shelves, and which will present information regarding the products to be sold.
Such a display should be self-powered, namely, free of any connection to the mains. It must have the ability to present high-resolution images at a wide range of viewing angles, sometimes on both of its sides, for viewing by observers approaching from different directions. Maintenance considerations require an operating period of at least 3 to 4 months without battery replacement. The advertising messages must be easily replaceable by an unskilled worker on site, without any difficulty. The display unit should be cost-effective; in other words, its cost should not exceed the price of the product(s) it promotes.